Sulfuric Lignin Research Articles

Novel Nanoarchitectures Based on Lignin Nanoparticles for Electrochemical Eco-Friendly Biosensing Development.

Novel nanoarchitectures based on lignin nanoparticles (LNPs) were designed and realized for electrochemical eco-friendly biosensing development. Two types of lignin nanoparticles were utilized for the modification of a gold bare electrode, namely organosolv (OLNPs) and kraft lignin (KLNPs) nanoparticles, synthetized from a sulfur-free and a sulfur lignin, respectively. The electrochemical behavior of LNP-modified electrodes was studied using two electrochemical techniques, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Compared to the gold bare electrode, an evident decrease in the faradaic current and increase of the ΔEp were observed in cyclic voltammograms. In addition, larger semicircles were registered in Nyquist plots. These results suggest a strong inhibition effect of the electron transfer reaction by LNPs layer, especially in the case of KLNPs. The modified electrodes, properly assembled with concanavalin A (ConA) and glucose oxidase (GOx), were successively tested as biosensing platforms for glucose, showing a sensitivity of (4.53 ± 0.467) and (13.74 ± 1.84) μA mM−1 cm2 for Au/SAMCys/OLNPs/ConA/GOx and Au/KLNPs/ConA/GOx biosensors, respectively. Finally, different layers of the KNLPs/ConA/GOx-modified Au electrode were tested, and the three-layered Au(KNLPs/ConA/GOx)3 showed the best analytical performance.

Facile new approach to high sulfur-content materials and preparation of sulfur–lignin copolymers

Chlorolignin can be copolymerized with sulfur in different ratios to form durable, recyclable materials.

Electrically conducting compound synthesized from lignin and sulfur

A thermostable polymer, called sulfur lignin, has been obtained when modifying lignin by reactions with elemental sulfur at elevated temperatures. Sulfur linkages are formed between the phenylpropane units of lignin in these reactions. The conductivity of polymers which have a conjugated structure can be increased by doping with electron acceptors or donors. The conductivity of sulfur lignin has been measured after doping with various dopants and from the results it is concluded that the doped sulfur lignin has the properties off a semi conductive polymer.